ヘッダー画像

タグ「Chronic contamination」

In vivo effects of chronic contamination with 137 cesium on testicular and adrenal steroidogenesis

Title: In vivo effects of chronic contamination with 137 cesium on testicular and adrenal steroidogenesis

Author: Elise Grignard, Yann Guéguen, Stéphane Grison, Jean-Marc A. Lobaccaro, Patrick Gourmelon, Maâmar Souidi

Reference: Archives of Toxicology , September 2008, Volume 82, Issue 9, pp 583-589

DOI: 10.1007/s00204-007-0268-4

Keywords : Steroidogenesis, Testis, Adrenal, Cesium, Chronic contamination

Abstract: More than 20 years after Chernobyl nuclear power plant explosion, radionuclids are still mainly bound to the organic soil layers. The radiation exposure is dominated by the external exposure to gamma-radiation following the decay of 137Cs and by soil-to-plant-to-human transfer of 137Cs into the food chain. Because of this persistence of contamination with 137Cs, questions regarding public health for people living in contaminated areas were raised. We investigated the biological effects of chronic exposure to 137Cs on testicular and adrenal steroidogenesis metabolisms in rat. Animals were exposed to radionuclide in their drinking water for 9 months at a dose of 6,500 Bq/l (610 Bq/kg/day). Cesium contamination decreases the level of circulating 17β-estradiol, and increases corticosterone level. In testis, several nuclear receptors messenger expression is disrupted; levels of mRNA encoding Liver X receptor α (LXRα) and LXRβ are increased, whereas farnesoid X receptor mRNA presents a lower level. Adrenal metabolism presents a paradoxical decrease in cyp11a1 gene expression. In conclusion, our results show for the first time molecular and hormonal modifications in testicular and adrenal steroidogenic metabolism, induced by chronic contamination with low doses of 137Cs.

URLhttp://link.springer.com/article/10.1007%2Fs00204-007-0268-4

Testicular steroidogenesis is not altered by 137 cesium Chernobyl fallout, following in utero or post-natal chronic exposure

Title: Testicular steroidogenesis is not altered by 137 cesium Chernobyl fallout, following in utero or post-natal chronic exposure

Author: Grignard E, Guéguen Y, Grison S, Dublineau I, Gourmelon P, Souidi M

Reference: Comptes Rendus Biologies, Volume 333, Issue 5, May 2010, Pages 416–423

doi: http://dx.doi.org/10.1016/j.crvi.2010.02.003

Keywords: Steroidogenesis, Cesium, Chronic contamination, Chernobyl, utero exposure, postnatal chronic exposure

Abstract: The testis is especially sensitive to pollutants, including radionuclides. Following the Chernobyl nuclear power plant accident, several of these radionuclides were emitted and spread in the environment. Subsequently, children presented some disruptions of the endocrine system. To determine whether these disruptions were due to 137 cesium (137Cs) exposure, the effects of chronic contamination with low doses of 137Cs in utero or from birth on testicular steroidogenesis in rats were studied. Contamination was continued for 9 months. No modification was observed in circulating level of hormones (17β-estradiol, testosterone, follicle-stimulating hormone, luteinizing hormone) following in utero or post-natal contamination. Expression of several genes involved in testicular steroidogenesis was affected (cyp19a1, fxr, sf-1), without modification of protein expression or activity. Our results suggest that growing organisms may be affected at the molecular level by 137Cs contamination at this post-accidental dose.

URL: http://www.sciencedirect.com/science/article/pii/S1631069110000466

▲ページの先頭へ戻る